summaryrefslogtreecommitdiff
path: root/src/sql.sml
blob: 59b4eac6c4dfadf1efdc9e73edcd19261aee7d57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
structure Sql :> SQL = struct

open Mono

val debug = ref false

type lvar = int

datatype func =
         DtCon0 of string
       | DtCon1 of string
       | UnCon of string
       | Other of string

datatype exp =
         Const of Prim.t
       | Var of int
       | Lvar of lvar
       | Func of func * exp list
       | Recd of (string * exp) list
       | Proj of exp * string

datatype cmp =
         Eq
       | Ne
       | Lt
       | Le
       | Gt
       | Ge

datatype reln =
         Known
       | Sql of string
       | PCon0 of string
       | PCon1 of string
       | Cmp of cmp

datatype lop =
         And
       | Or

datatype prop =
         True
       | False
       | Unknown
       | Lop of lop * prop * prop
       | Reln of reln * exp list
       | Cond of exp * prop

datatype chunk =
         String of string
       | Exp of Mono.exp

fun chunkify e =
    case #1 e of
        EPrim (Prim.String (_, s)) => [String s]
      | EStrcat (e1, e2) =>
        let
            val chs1 = chunkify e1
            val chs2 = chunkify e2
        in
            case chs2 of
                String s2 :: chs2' =>
                (case List.last chs1 of
                     String s1 => List.take (chs1, length chs1 - 1) @ String (s1 ^ s2) :: chs2'
                   | _ => chs1 @ chs2)
              | _ => chs1 @ chs2
        end
      | _ => [Exp e]

type 'a parser = chunk list -> ('a * chunk list) option

fun always v chs = SOME (v, chs)

fun parse p s =
    case p (chunkify s) of
        SOME (v, []) => SOME v
      | _ => NONE

fun const s chs =
    case chs of
        String s' :: chs => if String.isPrefix s s' then
                                SOME ((), if size s = size s' then
                                              chs
                                          else
                                              String (String.extract (s', size s, NONE)) :: chs)
                            else
                                NONE
      | _ => NONE

fun follow p1 p2 chs =
    case p1 chs of
        NONE => NONE
      | SOME (v1, chs) =>
        case p2 chs of
            NONE => NONE
          | SOME (v2, chs) => SOME ((v1, v2), chs)

fun wrap p f chs =
    case p chs of
        NONE => NONE
      | SOME (v, chs) => SOME (f v, chs)

fun wrapP p f chs =
    case p chs of
        NONE => NONE
      | SOME (v, chs) =>
        case f v of
            NONE => NONE
          | SOME r => SOME (r, chs)

fun alt p1 p2 chs =
    case p1 chs of
        NONE => p2 chs
      | v => v

fun altL ps =
    case rev ps of
        [] => (fn _ => NONE)
      | p :: ps =>
        foldl (fn (p1, p2) => alt p1 p2) p ps

fun opt p chs =
    case p chs of
        NONE => SOME (NONE, chs)
      | SOME (v, chs) => SOME (SOME v, chs)

fun skip cp chs =
    case chs of
        String "" :: chs => skip cp chs
      | String s :: chs' => if cp (String.sub (s, 0)) then
                                skip cp (String (String.extract (s, 1, NONE)) :: chs')
                            else
                                SOME ((), chs)
      | _ => SOME ((), chs)

fun keep cp chs =
    case chs of
        String "" :: chs => keep cp chs
      | String s :: chs' =>
        let
            val (befor, after) = Substring.splitl cp (Substring.full s)
        in
            if Substring.isEmpty befor then
                NONE
            else
                SOME (Substring.string befor,
                      if Substring.isEmpty after then
                          chs'
                      else
                          String (Substring.string after) :: chs')
        end
      | _ => NONE

fun ws p = wrap (follow (skip (fn ch => ch = #" "))
                        (follow p (skip (fn ch => ch = #" ")))) (#1 o #2)

fun log name p chs =
    (if !debug then
         (print (name ^ ": ");
          app (fn String s => print s
                | _ => print "???") chs;
          print "\n")
     else
         ();
     p chs)

fun list p chs =
    altL [wrap (follow p (follow (ws (const ",")) (list p)))
               (fn (v, ((), ls)) => v :: ls),
          wrap (ws p) (fn v => [v]),
          always []] chs

val ident = keep (fn ch => Char.isAlphaNum ch orelse ch = #"_")

val t_ident = wrapP ident (fn s => if String.isPrefix "T_" s then
                                       SOME (String.extract (s, 2, NONE))
                                   else
                                       NONE)
val uw_ident = wrapP ident (fn s => if String.isPrefix "uw_" s andalso size s >= 4 then
                                        SOME (str (Char.toUpper (String.sub (s, 3)))
                                              ^ String.extract (s, 4, NONE))
                                    else
                                        NONE)

val field = wrap (follow (opt (follow t_ident (const ".")))
                         uw_ident)
                 (fn (SOME (t, ()), f) => (t, f)
                   | (NONE, f) => ("T", f)) (* Should probably deal with this MySQL/SQLite case better some day. *)

datatype Rel =
         RCmp of cmp
       | RLop of lop

datatype sqexp =
         SqConst of Prim.t
       | SqTrue
       | SqFalse
       | SqNot of sqexp
       | Field of string * string
       | Computed of string
       | Binop of Rel * sqexp * sqexp
       | SqKnown of sqexp
       | Inj of Mono.exp
       | SqFunc of string * sqexp
       | Unmodeled
       | Null

fun cmp s r = wrap (const s) (fn () => RCmp r)

val sqbrel = altL [cmp "=" Eq,
                   cmp "<>" Ne,
                   cmp "<=" Le,
                   cmp "<" Lt,
                   cmp ">=" Ge,
                   cmp ">" Gt,
                   wrap (const "AND") (fn () => RLop Or),
                   wrap (const "OR") (fn () => RLop And)]

datatype ('a, 'b) sum = inl of 'a | inr of 'b

fun string chs =
    case chs of
        String s :: chs =>
        if size s >= 2 andalso String.sub (s, 0) = #"'" then
            let
                fun loop (cs, acc) =
                    case cs of
                        [] => NONE
                      | c :: cs =>
                        if c = #"'" then
                            SOME (String.implode (rev acc), cs)
                        else if c = #"\\" then
                            case cs of
                                c :: cs => loop (cs, c :: acc)
                              | _ => raise Fail "Iflow.string: Unmatched backslash escape"
                        else
                            loop (cs, c :: acc)
            in
                case loop (String.explode (String.extract (s, 1, NONE)), []) of
                    NONE => NONE
                  | SOME (s, []) => SOME (s, chs)
                  | SOME (s, cs) => SOME (s, String (String.implode cs) :: chs)
            end
        else
            NONE
      | _ => NONE

val prim =
    altL [wrap (follow (wrapP (follow (keep Char.isDigit) (follow (const ".") (keep Char.isDigit)))
                              (fn (x, ((), y)) => Option.map Prim.Float (Real64.fromString (x ^ "." ^ y))))
                       (opt (const "::float8"))) #1,
          wrap (follow (wrapP (keep Char.isDigit)
                              (Option.map Prim.Int o Int64.fromString))
                       (opt (const "::int8"))) #1,
          wrap (follow (opt (const "E")) (follow string (opt (const "::text"))))
               ((fn s => Prim.String (Prim.Normal, s)) o #1 o #2)]

fun known' chs =
    case chs of
        Exp (EFfi ("Basis", "sql_known"), _) :: chs => SOME ((), chs)
      | _ => NONE

fun sqlify chs =
    case chs of
        Exp (EFfiApp ("Basis", f, [(e, _)]), _) :: chs =>
        if String.isPrefix "sqlify" f then
            SOME (e, chs)
        else
            NONE
      | Exp (ECase (e, [((PCon (_, PConFfi {mod = "Basis", con = "True", ...}, NONE), _),
                         (EPrim (Prim.String (Prim.Normal, "TRUE")), _)),
                        ((PCon (_, PConFfi {mod = "Basis", con = "False", ...}, NONE), _),
                         (EPrim (Prim.String (Prim.Normal, "FALSE")), _))], _), _) :: chs =>
        SOME (e, chs)

      | _ => NONE

fun sqlifySqlcache chs =
    case chs of
      (* Could have variables as well as FFIs. *)
        Exp (e as (ERel _, _)) :: chs => SOME (e, chs)
      (* If it is an FFI, match the entire expression. *)
      | Exp (e as (EFfiApp ("Basis", f, [(_, _)]), _)) :: chs =>
        if String.isPrefix "sqlify" f then
            SOME (e, chs)
        else
            NONE
      | Exp (ECase (e, [((PCon (_, PConFfi {mod = "Basis", con = "True", ...}, NONE), _),
                         (EPrim (Prim.String (Prim.Normal, "TRUE")), _)),
                        ((PCon (_, PConFfi {mod = "Basis", con = "False", ...}, NONE), _),
                         (EPrim (Prim.String (Prim.Normal, "FALSE")), _))], _), _) :: chs =>
        SOME (e, chs)

      | _ => NONE

fun constK s = wrap (const s) (fn () => s)

val funcName = altL [constK "COUNT",
                     constK "MIN",
                     constK "MAX",
                     constK "SUM",
                     constK "AVG"]

val unmodeled = altL [const "COUNT(*)",
                      const "CURRENT_TIMESTAMP"]

val sqlcacheMode = ref false;

fun sqexp chs =
    log "sqexp"
    (altL [wrap prim SqConst,
           wrap (const "TRUE") (fn () => SqTrue),
           wrap (const "FALSE") (fn () => SqFalse),
           wrap (const "NULL") (fn () => Null),
           wrap field Field,
           wrap uw_ident Computed,
           wrap known SqKnown,
           wrap func SqFunc,
           wrap unmodeled (fn () => Unmodeled),
           wrap (if !sqlcacheMode then sqlifySqlcache else sqlify) Inj,
           wrap (follow (const "COALESCE(") (follow sqexp (follow (const ",")
                                                                  (follow (keep (fn ch => ch <> #")")) (const ")")))))
                (fn ((), (e, _)) => e),
           wrap (follow (const "(NOT ") (follow sqexp (const ")")))
                (fn ((), (e, _)) => SqNot e),
           wrap (follow (ws (const "("))
                        (follow (wrap
                                     (follow sqexp
                                             (alt
                                                  (wrap
                                                       (follow (ws sqbrel)
                                                               (ws sqexp))
                                                       inl)
                                                  (always (inr ()))))
                                     (fn (e1, sm) =>
                                         case sm of
                                             inl (bo, e2) => Binop (bo, e1, e2)
                                           | inr () => e1))
                                (const ")")))
                (fn ((), (e, ())) => e)])
    chs

and known chs = wrap (follow known' (follow (const "(") (follow sqexp (const ")"))))
                     (fn ((), ((), (e, ()))) => e) chs

and func chs = wrap (follow funcName (follow (const "(") (follow sqexp (const ")"))))
                    (fn (f, ((), (e, ()))) => (f, e)) chs

datatype sitem =
         SqField of string * string
       | SqExp of sqexp * string

val sitem = alt (wrap (follow sqexp (follow (const " AS ") uw_ident))
                      (fn (e, ((), s)) => SqExp (e, s)))
                (wrap field SqField)

val select = log "select"
             (wrap (follow (const "SELECT ") (list sitem))
                   (fn ((), ls) => ls))

val fitem = wrap (follow uw_ident
                         (follow (const " AS ")
                                 t_ident))
                 (fn (t, ((), f)) => (t, f))

val from = log "from"
           (wrap (follow (const "FROM ") (list fitem))
                 (fn ((), ls) => ls))

val wher = wrap (follow (ws (const "WHERE ")) sqexp)
           (fn ((), ls) => ls)

type query1 = {Select : sitem list,
              From : (string * string) list,
              Where : sqexp option}

val query1 = log "query1"
                (wrap (follow (follow select from) (opt wher))
                      (fn ((fs, ts), wher) => {Select = fs, From = ts, Where = wher}))

datatype query =
         Query1 of query1
       | Union of query * query

val orderby = log "orderby"
              (wrap (follow (ws (const "ORDER BY "))
                            (follow (list sqexp)
                                    (opt (ws (const "DESC")))))
                    ignore)

fun query chs = log "query"
                (wrap
                     (follow
                          (alt (wrap (follow (const "((")
                                             (follow query
                                                     (follow (const ") UNION (")
                                                             (follow query (const "))")))))
                                     (fn ((), (q1, ((), (q2, ())))) => Union (q1, q2)))
                               (wrap query1 Query1))
                          (opt orderby))
                     #1)
                chs

datatype dml =
         Insert of string * (string * sqexp) list
       | Delete of string * sqexp
       | Update of string * (string * sqexp) list * sqexp

val insert = log "insert"
             (wrapP (follow (const "INSERT INTO ")
                            (follow uw_ident
                                    (follow (const " (")
                                            (follow (list uw_ident)
                                                    (follow (const ") VALUES (")
                                                            (follow (list sqexp)
                                                                    (const ")")))))))
              (fn ((), (tab, ((), (fs, ((), (es, ())))))) =>
                  (SOME (tab, ListPair.zipEq (fs, es)))
                  handle ListPair.UnequalLengths => NONE))

val delete = log "delete"
                 (wrap (follow (const "DELETE FROM ")
                               (follow uw_ident
                                       (follow (follow (opt (const " AS T_T")) (const " WHERE "))
                                               sqexp)))
                       (fn ((), (tab, (_, es))) => (tab, es)))

val setting = log "setting"
                  (wrap (follow uw_ident (follow (const " = ") sqexp))
                        (fn (f, ((), e)) => (f, e)))

val update = log "update"
                 (wrap (follow (const "UPDATE ")
                               (follow uw_ident
                                       (follow (follow (opt (const " AS T_T")) (const " SET "))
                                               (follow (list setting)
                                                       (follow (ws (const "WHERE "))
                                                               sqexp)))))
                       (fn ((), (tab, (_, (fs, ((), e))))) =>
                           (tab, fs, e)))

val dml = log "dml"
              (altL [wrap insert Insert,
                     wrap delete Delete,
                     wrap update Update])

datatype querydml =
         Query of query
       | Dml of dml

val querydml = log "querydml" (altL [wrap dml Dml, wrap query Query])

end